/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: SelfIteratorNoPredicate.java,v 1.2.4.2 2005/09/14 19:45:21 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.axes;

import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.compiler.Compiler;

/**
 * This class implements an optimized iterator for
 * "." patterns, that is, the self axes without any predicates.
 * @see com.sun.org.apache.xpath.internal.axes.LocPathIterator
 * @xsl.usage advanced
 */
public class SelfIteratorNoPredicate extends LocPathIterator {
    static final long serialVersionUID = -4226887905279814201L;

    /**
     * Create a SelfIteratorNoPredicate object.
     *
     * @param compiler A reference to the Compiler that contains the op map.
     * @param opPos The position within the op map, which contains the
     * location path expression for this itterator.
     * @param analysis Analysis bits.
     *
     * @throws javax.xml.transform.TransformerException
     */
    SelfIteratorNoPredicate(Compiler compiler, int opPos, int analysis) throws javax.xml.transform.TransformerException {
        super(compiler, opPos, analysis, false);
    }

    /**
     * Create a SelfIteratorNoPredicate object.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public SelfIteratorNoPredicate() throws javax.xml.transform.TransformerException {
        super(null);
    }

    /**
     *  Returns the next node in the set and advances the position of the
     * iterator in the set. After a NodeIterator is created, the first call
     * to nextNode() returns the first node in the set.
     *
     * @return  The next <code>Node</code> in the set being iterated over, or
     *   <code>null</code> if there are no more members in that set.
     */
    public int nextNode() {
        if (m_foundLast)
            return DTM.NULL;

        int next;
        DTM dtm = m_cdtm;

        m_lastFetched = next = (DTM.NULL == m_lastFetched) ? m_context : DTM.NULL;

        // m_lastFetched = next;
        if (DTM.NULL != next) {
            m_pos++;

            return next;
        } else {
            m_foundLast = true;

            return DTM.NULL;
        }
    }

    /**
     * Return the first node out of the nodeset, if this expression is
     * a nodeset expression.  This is the default implementation for
     * nodesets.  Derived classes should try and override this and return a
     * value without having to do a clone operation.
     * @param xctxt The XPath runtime context.
     * @return the first node out of the nodeset, or DTM.NULL.
     */
    public int asNode(XPathContext xctxt) throws javax.xml.transform.TransformerException {
        return xctxt.getCurrentNode();
    }

    /**
     * Get the index of the last node that can be itterated to.
     * This probably will need to be overridded by derived classes.
     *
     * @param xctxt XPath runtime context.
     *
     * @return the index of the last node that can be itterated to.
     */
    public int getLastPos(XPathContext xctxt) {
        return 1;
    }

}
